JP2006289321A - Mercury removal method from mercury-polluted matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reducing method of a mercury level in mercury-polluted matter using microwave energy. <P>SOLUTION: This mercury removal method comprises processes for: (a) charging mercury-polluted matter into a microwave reactor; (b) supplying a gas flow to the microwave reactor for agitating the mercury-polluted matter; and (c) exposing the mercury-polluted matter to microwave radiation to raise the temperature at least to 357°C and forming a vapor phase containing mercury and treated matter. By using a double composition fluidized layer added with a microwave-sensitive matter containing no carbon besides the mercury-polluted matter, the mercury level and carbon level in the treating object substance are reduced at the same time. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for reducing mercury levels in mercury contaminated materials. In particular, the present invention relates to the use of microwave energy to reduce mercury levels in fly ash and adsorbent materials.

  Mercury is present in combustion gas streams from industrial incinerators and boilers, such as those used to burn coal for running water / electric power generation, or municipal solid waste treatment for steam generation or waste removal It is a known pollutant. Mercury's high toxicity to the environment is obvious enough, and mercury cleaning is therefore a necessary (but expensive) part of the flue gas treatment.

  Mercury cleaning of the flue gas stream can be done in several ways depending on complexity, cost, and efficiency. These methods include adsorbent (carbon or alkali) filtration, oxidation, and chlorination.

  Carbon adsorption filtration is known in the art and utilizes the known adsorption characteristics of fine coal, especially activated carbon. Several carbon adsorbent media technologies have been disclosed and implemented. For example, US Pat. No. 6,558,454 Chang et al. Contaminated the carbonaceous material with mercury at a temperature sufficient to activate the carbonaceous raw material to become an efficient adsorbent. Teaches how to inject into the gas stream. US Pat. No. 6,521,021 Pennline et al. Discloses a method for recirculation of semi-burning coal that is converted to a thermally activated carbon adsorbent and reintroduced into the primary combustion chamber. Wojtowicz et al., U.S. Pat.Nos. 6,103,205 and 6,322,613 both involve pyrolysis of carbonaceous feedstocks such as scrap tires, including means for regeneration of adsorbents by hot gas evaporation, and high Disclosed is a method for producing a carbon adsorbent by producing a concentrated mercury-rich gas stream.

  US Pat. No. 5,787,823 Knowles teaches the use of fly ash as an adsorbent, a by-product that is automatically generated by coal combustion due to its natural filtration characteristics, ie, small particle size and large surface-to-mass ratio . Knowles does not consider the possible effects of carbon (unburned fuel) in fly ash, nor the role played separately by fine coal absorption and carbon particle absorption. US Pat. No. 5,672,323 Bhat et al. Teaches the injection of activated carbon as an exhaust gas treatment for mercury removal.

  US Pat. No. 6,372,187 Madden et al. Discloses a method of performing particulate filtration as a means of removing mercury from a flue gas stream after the use of an alkaline adsorbent such as limestone.

  All adsorbent technology captures mercury-rich particulates in some form of baghouse or other similar means that separates the flue gas stream prior to release into the atmosphere. Inevitably, this mercury-rich particulate composite will contain mercury, adsorbents, and some residual fly ash that may have escaped during the early stages of fly ash removal. Ultimately, the particulate composite must be disposed of entirely by, for example, cementing, landfilling, or by treating the material to reduce volume or regenerate the adsorbent. In the case of adsorbent regeneration, the high cost of adsorbent exchange can be avoided or partially offset, and when reducing the volume, the mercury can be further concentrated to a substantially reduced mercury adsorbent volume. Can be confined or discarded efficiently. From an environmental point of view, ideally all mercury originally present in coal fuel should be collected in a molecular or elemental state that should be easy to manage.

  Considering the mercury-adsorbent mixture as an individual substance that needs to be treated, a means of removing mercury from this mixture can be considered. One such means is to perform pyrolysis of the mercury by heating the material to the mercury boiling point, followed by a mercury removal technique that is more efficient than the technique that originally produced the mercury-adsorbing material. It is. In many aspects, this is similar to the problem of removing mercury from mercury-contaminated soil and industrial materials.

  For example, US Pat. No. 6,268,590 Gale et al. Discloses a method of spirally passing dry granular material through an electrically heated furnace and retorting mercury from the dry granular material. A condenser is used to extract mercury vapor from the exhaust gas stream. Gale has the advantage that his process is continuous and size and complexity is more practical than the earlier methods disclosed in U.S. Patent No. 5,569,154 Navetta and U.S. Patent No. 1,599,372 Reed. Insist that.

  U.S. Pat. No. 6,024,931 Hanulik discloses a rotary tubular furnace that passes the material back to the combustion flame. Washburn et al., US Pat. Nos. 5,891,216 and 5,989,486 both teach a batch of retort processes involving the use of a stirring mechanism to assist in the release of evaporated mercury vapor. U.S. Pat. No. 5,782,188 Evans et al. Discloses a rotary furnace that functions as a pyrolytic incinerator in the absence of air and in which a combustible gas stream is concentrated into various product streams. US Pat. No. 5,632,863 Meador discloses a pyrolyzable method that can also handle used batteries. US Pat.No. 5,567,223 Lindgren et al. Further heated the decontaminated material by heating it in a furnace in the presence of selenium in a hot gas stream in order to turn the mercury contaminated material into mercury selenide. Explain the process left for use.

  Each of these methods meets the functional need to provide a process for reducing the mercury content in mercury pollutants, but there is a need for more efficient and economical methods. In addition, in some cases, such as fly ash treatment, it is often necessary to reduce the carbon level in the material. Therefore, there is a need for a method that can simultaneously reduce both the mercury and carbon content of substances contaminated with mercury.

  Accordingly, it is an object of the present invention to provide an improved method for reducing mercury from mercury contaminated materials. The method uses microwave energy.

  It is also an object of the present invention to provide a method for reducing mercury and carbon content in mercury pollutants using microwaves.

  A further object of the invention is the provision of the use of a bubbling fluidized bed reaction vessel in a process according to the invention.

  A further object of the invention is the provision of the use of a host layer material in a process according to the invention.

  The present invention discloses processes and means used to pyrolyze mercury from mercury contaminated solid mixtures of fly ash and adsorbent material using microwave energy. Using this process, the mercury is removed as hot vapor in a hot gas stream that is subsequently concentrated, leaving a solid residue, ie, the fly ash or adsorbent material, for reuse or clean disposal.

The process of the present invention involves the use of microwave energy to provide the heat necessary to evaporate mercury without the need for any flame or combustion gas. For example, the means used in processes such as metal fluidized bed containers that continuously supply and eliminate mercury contaminated materials and apply microwave energy are compact and have advantages over other retort and pyrolysis devices. It is an efficient device.

  In this case, the fundamental mechanism of microwave heating is dielectric and ohmic heating combustion, which uses both electrical displacement current and conduction current to convert electromagnetic energy directly into heat inside the material. The efficiency of this energy conversion depends on the dielectric properties of the material being processed. In this case, both fly ash and adsorbent material contain important receptor elements, mainly carbon, that can be rapidly heated in a controlled manner. This mercury evaporates when the temperature rises to about 357 ° C. (boiling point of mercury) under normal atmospheric pressure.

  The use of a bubbling fluidized bed reactor has several practical advantages. Its advantages include self-containment of microwave energy, natural material agitation to assist in the cleaning of mercury vapor, continuous inflow and outflow of material into the container, and natural separation of solids and gas streams.

  According to a first aspect, the present invention provides a method for reducing the level of mercury in a material contaminated with mercury, the method comprising placing the material contaminated with mercury into a microwave reactor; Providing the microwave reactor with a gas stream to agitate the mercury-contaminated material, and exposing the mercury-contaminated material to microwave radiation to bring the temperature to at least 357 ° C. And producing a vapor phase containing mercury and the treated material.

  According to a second aspect, the present invention provides a method for reducing mercury levels in a material contaminated with mercury, the method comprising placing a carbon-free material into a microwave reactor, Placing a mercury-contaminated substance into a microwave reactor, and a gas stream for agitating the mercury-contaminated substance and the carbon-free substance in the microwave reactor to form a mixture. Exposing the mercury contaminated material to microwave radiation to raise the temperature to at least 357 ° C. to create a vapor phase containing the mercury and the treated material. provide.

  According to a third aspect, the present invention is a method for reducing mercury and carbon levels in a mercury-contaminated material, wherein the method places the mercury-contaminated material in a microwave reactor. Providing the microwave reactor with a gas flow to agitate the mercury contaminated material; exposing the mercury contaminated material to microwave radiation to at least raise the temperature; And raising the temperature to 600 ° C. to produce a vapor phase containing mercury and the treated material.

  According to a fourth aspect, the present invention provides a method for reducing mercury and carbon levels in a mercury contaminated material, the method comprising placing a carbon-free material into a microwave reactor; A step of introducing the mercury-contaminated substance into a microwave reactor, and a gas for agitating the mercury-contaminated substance and the carbon-free substance to form a mixture in the microwave reactor; Providing a stream; and exposing the mercury contaminated material to microwave radiation to raise the temperature to at least 600 ° C. to create a vapor phase containing the mercury and the treated material. Provide a method.

  In a preferred embodiment of the first and third aspects, the method further comprises removing the vapor phase from the reactor, terminating the exposure to microwave radiation, and removing the treated material from the reactor. And introducing a new mercury-contaminated substance into the reactor. In a preferred embodiment of the second and fourth aspects, the method further comprises removing the vapor phase from the reaction vessel, terminating the exposure to microwave radiation, and removing the treated material from the reaction vessel. And a step of introducing a new carbon-free substance into the reaction vessel and a step of introducing a new mercury-contaminated substance into the reaction apparatus.

  More preferably, the above steps may be continuous and optional, and the method may further comprise introducing into the vapor phase with a filtration device such as a cyclonic separator. The method according to the invention may further comprise the step of capturing said vapor phase comprising mercury in a container.

  The microwave reactor used in the method of the present invention is preferably a fluidized bed reaction vessel, and the frequency of the microwave radiation may be about 300 mHz to about 30 GHz. Preferably, the frequency may be in the industrial scientific and medical (ISM) frequency band of about 915 MHz to 2450 MHz. The power level and process lifetime of microwave radiation sufficient to produce a specific energy may be between about 2 kW-h / t and about 20 kW-h / t.

  In the second and fourth aspects of the invention described above, the ratio of mercury contaminated material to carbon free material may be between about 25/75 and about 75/25. Preferably, this ratio is about 50/50. The mercury content of the mercury contaminated material may be up to 50% by weight and the mercury content of the material treated according to the method of the present invention may be less than about 10 ppb. Preferably, the mercury content of the treated material is less than 5 ppb. The carbon content of the mercury contaminated material may be up to 60% by weight.

  According to a sixth aspect, there is provided an apparatus specially employed for carrying out the method according to the present invention.

The method of reducing the mercury content of the mercury contaminated material according to the present invention uses microwave energy, which is efficient, economical and versatile.

These and other advantages of the present invention will become apparent upon reading the following detailed description and upon reference to the drawings.
While the invention will be described in connection with the illustrated embodiments, it will be understood that such embodiments are not intended to limit the invention. On the contrary, the intention is to cover all modifications, modifications, and equivalents that may be included within the spirit and scope of the invention as defined by the appended claims.

  Referring to FIG. 1, which illustrates a preferred embodiment of the present invention, a feed stream (1) of mercury contaminated material is continuously introduced into a microwave reaction vessel (2) functioning as a bubbling fluidized bed. The operation of a bubbling fluidized bed is known in the art. Essential to this preferred embodiment is the use of a dual composition fluidized bed comprising a host layer material in addition to the mercury contaminated material. The host layer material is selected as a mineral that is substantially free of carbon that is inert to the current process and can withstand the operating conditions of the process without chemical or mechanical effects. The host layer material is further described as having a sufficiently larger size distribution and density than the adsorbent material so that the fluidity of the adsorbent material in the reaction vessel is higher. Nevertheless, the kinetic effect of the host layer material is that the feed stream of the host layer material and the adsorbent material forms one integrated fluidized bed solvent in the reaction vessel. In addition to the size and density characteristics described above, the host layer material is selected to be a microwave sensitive material that can be directly heated by microwave energy, regardless of the properties of the other materials in the layer. It is clear that the use of this dual composition fluidized bed with a host material fraction of at least 50% by weight allows a process that can operate at significantly higher temperatures without dissolving or clinkering the carbon-rich adsorbent material. It was.

  The charged substance (1) in the reaction vessel (2) is injected into the base of the reactor through a nozzle system or an opening confined in a solid plate to effectively float the substance in the reaction vessel. A fluidized bed is formed by the flow (3). This aspect of fluidized bed operation is determined by the gas velocity required to effectively suspend the material and is known to those skilled in the art. This flowing gas passes through the reaction vessel and is discharged through a filtration device (4) such as a cyclonic separator. With this filtration device, all or most of the entrained fine particles are removed from the gas stream. This gas stream (5), which is substantially free of particulates, can then be subjected to further processing such as mercury removal.

  The material fed into the reaction vessel is continuously removed, for example by means of an overflow discharge pipe (6) and collected in a hopper (7) or other suitable vessel for further processing or use.

  The reaction vessel is a means for connecting a microwave generator (8), usually a waveguide (9), in which the atmosphere of the reaction vessel is efficiently removed from the waveguide. A waveguide having a microwave transmission barrier (10) for separation is installed.

  Microwave energy is supplied to a reaction vessel made of a metallic material suitable for efficiently containing a microwave field. When contacted with the fluidized material in the reaction vessel, a substantial portion of the microwave energy is converted to heat, thereby increasing the fluidized bed temperature. The coupling efficiency of the microwave energy to the fluidized bed material is controlled by a tuning device (11) attached to the waveguide. Such a tuning device can also be electrically controlled to continuously optimize output transmission. When the temperature of the fluidized bed reaches about 357 ° C., the boiling point of mercury under normal atmospheric pressure, the mercury passes through the vapor phase and is discharged from the vessel along with a flowing gas stream. The flowing gas may be ambient air if it is desired to burn the bed material, or the gas is inert to mercury or carbon so that the heating process of the reaction vessel cannot burn the adsorbent material. It may be selected to be active (eg, nitrogen).

  The hot gas stream present in the reaction vessel passes through the cyclonic separator described above. Since the gas temperature is maintained above the boiling point of mercury, mercury vapor is sent to the gas outlet (5) where it is filtered for concentration or recovery.

  Combine fine particles from the cyclone separator (12) with other waste solids (7).

  As is known to those skilled in the art of fluidized beds, various valves (13) are used for the flow of material to and from the reaction vessel (and cyclone separator) in order to prevent gas leakage.

  Various devices (14) are attached to the device for monitoring and controlling the heating process. Temperature probes are installed in the fluidized bed and at various locations on the supply and discharge lines including the gas injection and discharge lines. Attach gas pressure and product monitors to all gas lines. The measurement of the material flow through the reaction vessel is performed by a flow meter or a mass meter. A system fitted with a device in this manner can be operated manually or automatically to maintain system operation within the minimum-maximum boundary.

  The incorporation of the host layer material is performed by a separate feed stream (15) combined with the contaminated material injection stream and is controlled to make up for the loss of host layer material by the reactor. If necessary, the host layer material may be separated from the reconstructed adsorbent material (eg, flotation or gravity separation) and recycled to the injection hopper for reuse.

  According to a preferred embodiment of the present invention, when an inert gas is used for fluidization, the mercury-contaminated material is efficiently purged without burning, allowing the adsorbent material to be reused. You can also. The mercury so released can also be efficiently captured as described above. This mercury retorting method has significant advantages over other heating means, primarily due to the efficiency and rapidity of heat generation using microwave energy.

  The apparatus shown schematically in FIG. 1 was assembled to treat a certain amount of coal-fired fly ash known to contain mercury. The microwave frequency was 915 MHz. The fluidizing gas was ambient air.

  The fly ash raw material was processed at a temperature of about 820 ° C. This material was passed through the reaction vessel at a rate of about 6 lbs / min during a test time of about 400 minutes.

The amount of mercury contained in this raw material was measured and found to be 79 ppb. The unburned carbon content, characterized as LOI (loss on ignition), was measured to be 8.5%.

  Samples of treated ash were taken periodically throughout the experiment and their mercury content was measured. The obtained results are shown in Table 1 below. The LOI of the treated material was 1.5%.

水銀の測定値

Mercury measurements

  When this process reached a steady state with respect to mercury state changes, the mercury content of the exhaust (product and cyclone waste) was substantially reduced from its initial value. It can be fully expected that by reducing the feed rate, the average residence time of the substance in the reactor will be extended and the mercury level could be further reduced. Nevertheless, the effectiveness of the process in reducing mercury concentration is clear.

  The apparatus shown schematically in FIG. 1 was assembled to treat a certain amount of coal-fired fly ash known to contain mercury. The microwave frequency was 915 MHz. The fluidizing gas was ambient air.

  The fine coal raw material was treated at a temperature of about 820 ° C. During a test time of about 500 minutes, this material was passed through the reaction vessel at a rate of about 6 lbs / min.

  The amount of mercury contained in this raw material was measured and found to be 33 ppb. The measured unburnt carbon content, characterized as LOI (loss on ignition), was 17.5%.

  Samples of treated ash were taken periodically throughout the experiment and their mercury content was measured. The obtained results are shown in Table 2 below. The LOI of the treated material was 0.4%.

水銀の測定値

Mercury measurements

  The apparatus shown schematically in FIG. 1 was assembled to treat a certain amount of coal-fired fly ash known to contain mercury. The microwave frequency was 915 MHz. The fluidizing gas was ambient air.

  The fly ash raw material was processed at a temperature of about 820 ° C. This material was passed through the reaction vessel at a rate of about 6 lbs / min during a test time of about 400 minutes.

  The amount of mercury contained in this raw material was measured and found to be 142 ppb. The measured unburnt carbon content, characterized as LOI (loss on ignition), was 4.5%.

  Samples of treated ash were taken periodically throughout the experiment and their mercury content was measured. The results obtained are shown in Table 3 below. The final LOI was 0.3%.

水銀の測定値

Mercury measurements

  As is apparent from the foregoing examples, the process disclosed herein is effective in reducing mercury concentration regardless of the initial mercury content of the material or its LOI.

  The examples described herein were performed at a microwave frequency of 915 MHz, which is within the range of the electromagnetic ISM (industrial scientific medical) frequency band for unlicensed operations that can be easily used, but the main effect is micro It is within the scope of the present invention that generally any frequency within the microwave region may be used so that it falls within the resonant reaction vessel in a manner known to those skilled in the art of waves.

  In the above example, ambient air was used as the flowing gas because the treatment operation was mainly aimed at burning unburned carbon in the ash and vaporizing mercury. In direct analogy with the above example, as implemented by the inventors, instead of ambient air, the substance can be heated efficiently without burning (due to microwave absorption) such as nitrogen Inert gas may be used.

  Furthermore, in the above example, an operating temperature of about 820 ° C. is used for the purpose of burning unburned carbon contained in ash, but it is only necessary to achieve 357 ° C. for the vaporization of mercury. (Under normal atmospheric pressure), therefore, the process according to the present invention can be operated at any temperature above 357 ° C., as long as the temperature at which the ash antibiotics are notably dissolved or agglomerated is exceeded. Also good. Such conditions will be known to those skilled in the art of metallurgical processing of minerals and ores.

  In the above example, a reaction vessel operating on the known principle of a bubbling fluidized bed is used, but it is possible to use other vessel designs that can be used as microwave containing vessels. Within the scope of the invention. This includes, but is not limited to, rotary furnaces, fluid drums, multimode cavity resonators, filled tubes, and conveyor cavity resonators that transmit fluidized beds.

  Thus, it is clear that in accordance with the present invention, there has been provided a method for reducing the mercury content of a material contaminated with mercury using microwave energy, which fully satisfies the above needs and advantages. is there. Although the present invention has been described in conjunction with the illustrated embodiments, it will be apparent to those skilled in the art that many changes, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alterations, modifications and variations that fall within the spirit and broad scope of the present invention.

1 illustrates an apparatus for implementing an embodiment of the method described in the present invention.

Claims (33)

A method for reducing the level of mercury in a material contaminated with mercury, comprising:
(a) placing a substance contaminated with mercury into a microwave reactor;
(b) introducing a gas flow from substantially below the mercury-contaminated substance, wherein the gas and the mercury-contaminated substance are fluidized in the microwave reactor. And wherein the gas stream causes agitation to the mercury contaminated material;
(c) exposing the mercury contaminated material to microwave radiation to raise the temperature to at least about 357 ° C. to produce a vapor phase of the mercury and the treated material;
Including a method. A method for reducing the level of mercury in a material contaminated with mercury, comprising:
(a) placing a carbon-free material into a microwave reactor;
(b) placing a substance contaminated with mercury into the microwave reactor;
(c) introducing a gas stream from substantially below the mercury-contaminated substance, wherein the gas and the mercury-contaminated substance are fluidized in the microwave reactor. Forming a mixture by causing the gas stream to agitate the mercury-contaminated material and the carbon-free material; and
(d) exposing the mercury contaminated material to microwave radiation to raise the temperature to at least about 357 ° C. to produce a vapor phase of the mercury and the treated material;
Including a method. A method for reducing mercury and carbon levels in a material contaminated with mercury, comprising:
(a) placing a substance contaminated with mercury into a microwave reactor;
(b) introducing a gas flow from substantially below the mercury-contaminated substance, wherein the gas and the mercury-contaminated substance are fluidized in the microwave reactor. And wherein the gas stream causes agitation to the mercury contaminated material;
(c) exposing the mercury contaminated material to microwave radiation to raise the temperature to at least about 600 ° C. to produce a vapor phase of mercury and the treated material;
Including a method. A method for reducing mercury and carbon levels in a material contaminated with mercury, comprising:
(a) placing a carbon-free material into a microwave reactor;
(b) placing a substance contaminated with mercury into the microwave reactor;
(c) introducing a gas stream from substantially below the mercury-contaminated substance, wherein the gas and the mercury-contaminated substance are fluidized in the microwave reactor. Forming a mixture by causing the gas stream to agitate the mercury-contaminated material and the carbon-free material; and
(d) exposing the mercury contaminated material to microwave radiation to raise the temperature to at least about 600 ° C. to produce a vapor phase comprising mercury and the treated material;
Including a method. The method according to claim 1 or 3, further comprising:
(d) removing the vapor phase from the reactor;
(e) ending the exposure to microwave radiation;
(f) removing the treated material from the reactor;
(g) introducing new mercury contaminated material into the reactor;
Including a method. The method according to claim 2 or 4, further comprising:
(e) removing the vapor phase from the reactor;
(f) terminating the exposure to microwave radiation;
(g) removing the treated material from the reactor;
(h) introducing new carbon-free material into the reactor;
(i) introducing new mercury contaminated material into the reactor;
Including a method.   6. The method according to claim 5, wherein steps (d) to (g) are steps that occur successively in the method.   7. The method according to claim 6, wherein steps (e) to (i) are steps that occur successively in the method.   7. A method according to claim 5 or 6, further comprising the step of introducing the vapor phase into a filtration device.   10. A method according to claim 9, wherein the filtration device is a cyclonic separator.   7. A method according to claim 5 or 6, further comprising the step of trapping a vapor phase containing mercury in the container.   The method according to any one of claims 1 to 4, wherein the microwave reactor is a fluidized bed reaction vessel.   3. A method according to claim 1 or 2, wherein the microwave radiation has a frequency of 300 MHz to 30 GHz.   14. The method according to claim 13, wherein the frequency is between 900 MHz and 3000 MHz.   14. The method of claim 13, wherein the frequency is an industrial scientific medical (ISM) frequency band between about 915 MHz and 2450 MHz.   5. A method according to claim 3 or 4, wherein the microwave radiation has a frequency of 300 MHz to 30 GHz.   The method according to claim 16, wherein the frequency is 900 MHz to 3000 MHz.   17. The method of claim 16, wherein the frequency is an industrial scientific medical (ISM) frequency band between about 915 MHz and 2450 MHz.   3. A method according to claim 1 or 2, wherein the power level of microwave radiation is sufficient to produce a specific energy of about 2 kW-h / t to about 20 kW-h / t, and How to use process life time.   20. The method of claim 19, wherein the microwave radiation has a power level and a process life time of about 2 kW-h / t to about 5 kW-h / t.   5. A method as claimed in claim 3 or 4, wherein the power level of the microwave radiation is sufficient to produce a specific energy of about 4 kW-h / t to about 20 kW-h / t, and How to use process life time.   5. A method according to claim 2 or 4, wherein the method uses a ratio of mercury contaminated material to carbon free material, 25:75 to 75:25.   23. The method of claim 22, wherein the ratio is about 50:50.   5. A method according to any one of the preceding claims, wherein the gas is selected from the group consisting of ambient air and gases inert with respect to mercury and carbon.   25. The method of claim 24, wherein the inert gas with respect to mercury and carbon is selected from nitrogen and carbon dioxide.   3. A method according to claim 1 or 2, wherein the gas is inert with respect to the mercury and carbon.   5. The method according to any one of claims 1 to 4, wherein the mercury level in the mercury contaminated material in the method is up to about 50% by weight.   5. A method according to any one of claims 3 to 4, wherein the carbon level in the mercury contaminated material in the method is up to about 60% by weight.   5. A method according to claim 2 or 4, wherein the carbon-free material is a microwave sensitive material having a size distribution and density greater than that of a material contaminated with mercury comprising manganese dioxide. A method selected from the group consisting of silica, metal oxides, siliceous oxides, and mixtures thereof.   30. The method of claim 29, wherein the carbon-free material is selected from the group consisting of manganese dioxide and silica.   5. A method according to any one of claims 1 to 4, wherein the treated material has a mercury content of less than about 10 ppb.   32. The method of claim 31, wherein the mercury content is less than about 5 ppb. A method for reducing mercury levels in a mercury-contaminated substance in a process that can be continuously maintained, comprising:
(a) placing a substance contaminated with mercury into a microwave reactor;
(b) introducing a gas flow from substantially below the mercury-contaminated material, wherein the material contaminated with gas mercury in the microwave reactor forms a fluidized bed in the step; Forming and causing the gas stream to agitate the mercury contaminated material;
(c) exposing the mercury contaminated material to microwave radiation to raise the temperature to at least about 357 ° C. to produce a vapor phase comprising mercury and the treated material;
Including a method.

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